Studying the biological activity of fungi is crucial to discovering their potential for the treatment and prevention of various diseases. The diverse composition and various substances they produce are the basis of their application in medicine. Pullulan can be used as blood plasma substituent, carrier in drug delivery systems. Chitin possess antimicrobial, anticoagulant and antitumor activities. Inotodiol and the other substances from Inonotus obliquus possess strong cytotoxic activity against breast and gastric cancer. Camptothecin derivatives are used for treatment of ovarian and colorectal cancers. In our study we used a strain Antarctic yeasts Cryptococcus laurentii AL65. We found out that these psychrophilic yeasts possess antineoplastic activity. Their action is observed in solid tumors -bladder cancer. Along with their cytotoxic effects yeasts possess a very good safety profile and can be part of future antitumor therapy.